How can caffeine overdose lead to death?

Caffeine is a central nervous system stimulant that, when consumed in excessive amounts, can lead to significant physiological disturbances. An overdose of caffeine primarily affects the cardiovascular system, potentially leading to life-threatening conditions such as cardiac arrhythmias.

In cases of caffeine overdose, the stimulant effect can increase heart rate and provoke various arrhythmias, like tachycardia or even more severe rhythms such as ventricular fibrillation, which can result in cardiac arrest. The mechanism behind these arrhythmias involves increased catecholamine release, heightened excitability of myocardial cells, and altered conduction pathways within the heart.

While other options represent serious conditions that can arise in the context of severe caffeine toxicity, cardiac arrhythmias are particularly critical as they can lead directly to sudden death. Alterations in respiratory function or coma can occur, but they are less directly linked to an immediate lethal risk compared to the cardiac complications stemming from arrhythmias.

Severe dehydration is typically not a primary concern in caffeine overdose scenarios compared to its immediate cardiovascular effects. Thus, the most direct and dangerous consequence of caffeine overdose, which can lead to death, is indeed the development of cardiac arrhythmias.